Leg Drive Measuring and Training Apparatus for Baseball and Softball Hitters

ABSTRACT

An apparatus for measuring a ball hitter&#39;s “leg drive” for training and coaching purposes and for developing a strong leg drive (ground force). The apparatus includes a ground engaging lower plate and an upper plate that supports the hitter&#39;s foot. The plates are slidingly secured to one another such that the upper plate is linearly moveable relative to the lower plate. A force measuring element is provided between the upper and lower plates. The apparatus is used by the hitter stepping on the upper plate and pushing while hitting, thereby linearly moving the upper plate against the lower plate and the force measuring element, which may comprise a load cell or a spring mechanism. The apparatus provides an output indicative of the hitter&#39;s leg drive (ground force) level. In some embodiments, an audible sound is generated when a preselected leg drive level is reached.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method for measuringthe “leg drive” or “ground force” of, for example, a baseball orsoftball hitter, for training and coaching purposes, and for developinga strong leg drive that ultimately increases energy that creates morepower and bat speed.

2. Background

As is well known to those familiar with the games of baseball andsoftball, the hitter hits a baseball thrown by a pitcher who intends tomake the batter miss. It is, of course, desirable to hit the ball withas much power as possible and the longest distance. In this regard, ahitter pushes against the ground and thereby “drives” with his or herlegs to propel his or her body into a rotational manner to ultimatelyswing the bat more forcibly. The force (Ground Force) exerted by hittersagainst the ground is known as the hitter's “leg drive”. It has beenfound that the speed at which the bat is swung can be increased byincreasing the hitter's leg drive force (Ground Force).

Devices for measuring “leg drive” are currently known. For example, U.S.Pat. No. 6,616,556 (Osmundson) discloses a method and apparatus formeasuring leg drive wherein a pressure transducer element or gauge isintegrated into a pitching rubber and wherein the output of the pressuregauge is used for creating a “leg drive” pressure profile. The device isuseful in evaluating baseball pitchers, determining if a pitcher hasrecovered from injury, determining if a pitcher is tiring during a game,providing an indication of the pitchers ability to throw hard, fortraining and coaching purposes for developing a strong leg drive, etc.However, this apparatus cannot be used without a display device such asa computer making it generally cumbersome for use outdoors on baseballfields. Because this apparatus locates the pressure transducerelement(s) along the front surface of the pitching rubber, the output isdependent on the pitcher making proper contact therewith. Accordingly,this apparatus could potentially be unreliable.

A need exists for an improved leg drive (Ground Force) measuring andtraining apparatus which is generally easily usable and which reliablyprovides a consistent output indicative of the leg drive (Ground Force).

SUMMARY OF THE INVENTION

In one exemplary embodiment, the hitting training apparatus of thepresent invention comprises a lower ground engaging plate and an upperhitter's foot supporting plate. The lower and upper plates are linearlymovable relative to each other. The present invention further comprisesa force measuring element provided between the upper and lower plates.When pushed by a hitter during the act of swinging, for example, a bat,the upper plate moves linearly and the force element exhibits an outputindicative of the hitter's leg drive.

The present invention may further comprise a plurality of slidessandwiched between the upper and lower plates, wherein each of theslides is secured to each of the lower and upper plates whereby thelower and upper plates are linearly movable relative to each other.Further, preferably, a pair of oval holes are provided extending throughthe upper plate and a shoulder bolt is received through each of theholes and is secured to the lower plate, whereby the upper and lowerplates are maintained in parallel adjacent to one another and the linearmovement is limited by the size of the holes.

The force measuring element of the present invention may comprise a loadcell providing an electrical output indicative of the hitter's leg drive(Ground Force) and the output can further include an audible sound.

The element can also comprise a spring mechanism. The spring mechanismincludes a cylindrical shell having a bore extending therethrough. Aplunger is located in the bore and projects beyond a terminal end of theshell. The plunger abuts the upper plate. A spring is located in thebore and urges the plunger against the upper plate with a spring force.A threaded fastener is provided adjacent the spring. The fastener isadapted to engage the spring and thereby adjust a length of the spring,whereby the spring force is selectively adjustable. The output caninclude an audible sound generated by the upper plate hitting the shellwhen the spring force is overcome.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features and objects of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of the embodiments of the invention taken in conjunctionwith the accompanying drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of a leg drive(Ground Force) measuring and training apparatus constructed inaccordance with the principles of the present invention;

FIG. 2 is a top plan view of the apparatus shown in FIG. 1;

FIG. 3 is a side elevation view of the apparatus shown in FIG. 1;

FIG. 4 is a perspective view of a second embodiment of a leg drivemeasuring and training apparatus constructed in accordance with theprinciples of the present invention;

FIG. 5 is a top plan view of the apparatus shown in FIG. 4;

FIG. 6 is a side elevation view of the apparatus shown in FIG. 4;

FIG. 7 is a perspective exploded view of the apparatus shown in FIG. 4;

FIG. 8 is a top plan view of the lower ground engaging plate of theapparatus shown in FIG. 4;

FIG. 9 is a top plan view of the upper hitter's foot supporting plate ofthe apparatus shown in FIG. 4;

FIG. 10 is a front elevation exploded view of the apparatus shown inFIG. 4;

FIG. 11 is a side elevation exploded view of the spring force measuringand sound generating mechanism used in the embodiment of FIGS. 4-6; and

FIG. 12 is a cross-sectional view of an assembled mechanism shown inFIG. 11.

Corresponding reference characters indicate corresponding partsthroughout several views. Although the exemplification set out hereinillustrates embodiments of the invention, in several forms, theembodiments disclosed below are not intended to be exhaustive or to beconstrued as limiting the scope of the invention to the precise formsdisclosed.

DETAILED DESCRIPTION

A leg drive measuring and training apparatus constructed in accordancewith the principles of the present invention is shown in the drawingsand generally designated by the numeral 10. Apparatus 10 can be used bybaseball and softball hitters and coaches for measuring leg drive(ground force), for training purposes and for increasing leg drive(ground force). Although described herein for use by baseball andsoftball hitters and coaches, it should be understood that the apparatus10 can be used for measuring leg drive in other sports and otherapplications.

Apparatus 10 includes a ground engaging lower plate 12 and an upperplate 14 on which a hitter's foot is supported. Plates 12, 14 arepreferably made of 3/16 inch thick steel which have been surface treatedto prevent rust such as by painting, galvanizing, etc. Plates 12, 14 canalso be made of other materials including, for example, aluminum,plastics and nylon etc. The ground engaging lower plate is rectangularhaving a front edge 12F, a left edge 12L, a right edge 12R and a backedge 12B. Ground engaging lower plate 12 is preferably about 15×17inches. The foot supporting upper plate 14 is also rectangular having afront edge 14F, a left edge 14L, a right edge 14R and a back edge 14B.Upper plate 14 is preferably about 13×15 inches.

Plates 12 and 14 are slidingly secured to one another whereby, when thelower plate 12 is engaged or otherwise secured to the ground, upperplate 14 is slidingly linearly movable along a plane parallel with theplates 12, 14 and in a direction as indicated by double-headed arrow 16.In this regard, a pair of slides 18 is provided and is sandwiched andsecured between the upper and lower plates 12, 14. Slides 18 can becenter mount ball-bearing drawer slides having a lower slide bar 20slidingly secured to an upper slide bar 22 in a known and customarymanner Drawer slides 18 are well known, commercially available, and arecommonly used for slidingly supporting cabinet drawers and otherobjects. It is contemplated that other slide devices, mechanisms andstructures can equally be used which are capable of slidingly securingupper and lower plates 12, 14 to one another and allowing them to slidelinearly relative to each other in a plane as indicated by arrow 16.

As best seen in FIGS. 7-11, the lower slide bars 20 of each of theslides 18 are secured to the lower plate 12 with spring/roll pinfasteners 24 which extend through holes (not shown) in the lower slidebars 20 and holes 26 in the lower plate 12. Similarly, the upper slidebars 22 of each of the slides 18 are secured to the upper plate 14 withspring/roll pin fasteners 24 which extend through holes 27 in the upperslide bars 22 and holes 28 in the upper plate 14. For added strength,the spring/roll pin fasteners can be tack welded in their respectiveholes.

The lower and upper plates 12, 14 are retained together/adjacent oneanother with the slides 18 sandwiched therebetween with four shoulderbolts 30. Shoulder bolts 30 include a tool engagement head 32, a centralshaft 34 and a threaded terminal end 36. Shoulder bolts 30 are receivedthrough oval holes/openings 38 in the upper plate 14 and the threadedterminal ends 36 thereof threadingly engage and are secured in threadedholes 40 in the lower plate 12. The length of the central shafts 34 issuch that, when the shoulder bolts 30 are securely engaged in holes 40,the tool engagement heads 32 are located a short distance/slightly abovethe upper plate 14. Preferably, oval openings 38 are about 0.390 inch inthe short direction and about 0.465 inch in the long direction. Alsopreferably, the diameter of the shoulder bolt central shaft is about0.375 inch. Accordingly, because the shoulder bolt heads 32 are largerthan the oval openings 38, plates 12 and 14 are maintained adjacent andparallel to one another with the slides 18 sandwiched therebetween.Also, because the oval openings are larger in the long direction, theupper plate 14 is freely slidable/movable as indicated by arrow 16 butlimited to a travel distance of the long length of each opening 38 lessthe diameter of the respective central shaft 34, or about 0.090 inch(0.465-0.375=0.090). Of course, the tolerances of the several componentsare such that the upper plate 14 will slide freely relative to the lowerplate 12 without excessive frictional engagement or binding.

Mounting holes 50 are provided in and extend through the lower plate 12.Mounting holes 50 are adapted to receive a mounting stake or screwtherethrough whereby, during use, the apparatus 10 can be secured to theground, a batter's box, interior floors, etc. The upper plate 14 isprovided with access holes 52 which are aligned with and which provideaccess to the mounting holes thereunder.

Referring now to the embodiment shown in FIGS. 1-3, the apparatus 10includes a force/compression load cell 54 secured by fasteners or othersuitable means between the lower plate 12 and upper plate 14.Preferably, a bracket 56 is secured to the lower plate 12 by welding,fasteners or other suitable means and the load cell 54 is securedthereto with fasteners (not shown) for locating the load cellsensor/plunger adjacent the upper plate 14 as needed. A stud 58 can bewelded or otherwise secured to the upper plate 14 and the load cellsensor/plunger can be located adjacent thereto.

Force/compression load cells are commercially available and well knownto those skilled in the art and are capable to providing an analog ordigital electrical output responsive to the compressive force beingexerted thereon. Load cell 54 is electrically connected to a computer orother similar device (not shown) whereat the output thereof can bestored, displayed and transmitted as needed or desired. As should now beappreciated, load cell 54 acts as a stop for the linearly moveable upperplate 14 relative to the lower plate 12 and measures the appliedforce/leg drive therebetween.

The apparatus 10 of FIGS. 1-3 is used by a baseball or softball hitterby placing his/her foot on the upper plate 14. The hitter then goes intothe swing pattern, as is known and customary, pushing against upperplate 14 with his or her back foot. The hitter's leg drive/force (GroundForce) against upper plate 14 thereby causes the upper plate 14 to slidetoward and against the load cell 54. The load cell 54, therefore,effectively measures and provides an output responsive to the hitter'sleg drive which can be stored, displayed and transmitted. The measuredleg drive force can then, of course, be used as needed for training andother purposes.

Referring now to the embodiment shown in FIGS. 4-12, the apparatus 10includes an adjustable spring force/compression measuring and soundgenerating mechanism 60. As shown in FIGS. 11 and 12, mechanism 60includes a cylindrical shell 61 having a bore 62 extending therethroughbetween axial terminal ends 64, 66. Bore 62 includes a plunger receivingsection 68 adjacent terminal end 64, a threaded section 70 adjacentterminal end 66 and a spring receiving section 72 between terminal end64 and terminal end 66. An annular seat 74 is provided between theplunger receiving section 68 and the spring receiving section 72.

Plunger 76 is received through the threaded section 70 and the springreceiving section 72 and is located within plunger receiving section 68whereat the annular shoulder 78 thereof is seated against annular seat74. In this position, the terminal end 80 of plunger 76 extends beyondthe terminal end 64 of the shell 61, preferably, a distance which isequal to or greater than the travel distance of the upper plate 14described hereinabove. Spring 82 is received through the threadedsection 70 and is located within the spring receiving section 72 andabutting the head 84 of plunger 76. Spring 82 is compressed and an alienscrew 86 is threadingly received in threaded section 70 of bore 62. Ascan be appreciated, alien screw 86 maintains spring 82 in compressionwhich, in turn, maintains the plunger shoulder 78 seated against theannular seat 74. Additionally, by threadingly axially adjusting alienscrew 86 along the bore threaded section 70, the force F required tomove plunger 76 against the spring 82 and lift the plunger head 84 offof the annular seat 74 is selectively adjustable. Alternatively, a thumbscrew 87 can be used, as shown in FIGS. 4-6 for selectively turning andadjusting the spring force by hand.

Similar to the embodiment using a load cell 54 described hereinabove,the cylindrical shell 61 is secured by welding, fasteners or othersuitable means between the lower plate 12 and upper plate 14.Cylindrical shell 61 is preferably welded to the lower plate 12 as shownwith its longitudinal axis being parallel with the upper plate 14 lineardirection of travel as indicated by arrow 16, and with its terminal end64 adjacent the upper plate back edge 14B. The terminal end 64 is spacedfrom the upper plate back edge 14B a distance which is less than theupper plate travel distance described hereinabove, and with the plungerterminal end 80 abutting the back edge 14B.

The embodiment of FIGS. 4-12 is similarly used by a hitter by placinghis/her foot on the upper plate 14 and performing the customary batswing mechanics. In this embodiment, the hitter's leg drive/force(ground force) causes the upper plate 14 to be forced against theplunger 76. When a sufficient leg drive/force F is exerted to overcomethe spring force, plunger 76 axially retracts into the cylindrical shell61 and the upper plate 14 slidingly moves in the direction of arrow 16until its back edge 14B abuts/hits the shell terminal end 64. The backedge 14B hitting the shell terminal end 64 generates an audible soundoutput which is transmitted through the lower and upper plates 12, 14and which thereby notifies the hitter that the spring force has beenovercome. As should now be appreciated, the spring force can becalibrated so that, depending on the axial location of the screw 86, 87the hitter will know by apparatus 10 generating such an audible soundoutput, the value of the drive force required to overcome the springforce and generate the audible sound output. Accordingly, the apparatus10 can thereby be used as needed or desired for training and improvingthe hitter's leg drive (Ground Force).

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles.

1. A hitting training apparatus comprising: a ground-engageable lowerplate; an upper plate supportable of a hitter's foot, said upper platedisposed in parallel to said lower plate and slidably connected to saidground plate; and a force measuring element operably disposed betweenand functionally attached to at least one of said lower plate and saidupper plate, said force measuring element operable to indicate a forceimposed between said ground lower plate and said upper plate and bywhich relative movement between said lower plate and said upper plate isinduced.
 2. The apparatus of claim 1, further comprising a plurality ofslides sandwiched between said upper plate and said lower plate, andwherein each of said slides is secured to each of said lower plate andsaid upper plate whereby said lower and upper plates are linearlymovable relative to each other.
 3. The apparatus of claim 1, wherein apair of openings is provided through the upper plate, and furthercomprising a shoulder bolt received through each of said openings and issecured to the lower plate, whereby said upper plate and said lowerplate are maintained in parallel and adjacent to one another and saidrelative movement is linear and limited by the size of said openings. 4.The apparatus of claim 3, wherein said openings are oval shaped.
 5. Theapparatus of claim 1, wherein said force measuring element is a loadcell from which is generated an electrical output indicative of a forceimparted by the hitter's leg drive.
 6. The apparatus of claim 1 whereinsaid force measuring element generates an output indicative of ahitter's leg drive reaching a preselected force level.
 7. The apparatusof claim 6 wherein said output comprises an audible sound.
 8. Theapparatus of claim 1, wherein said force measuring element comprises: acylindrical shell having an axial terminal end and an axial boreextending therethrough; a plunger located in said bore and projectingbeyond said shell terminal end, said plunger engaged with said upperplate; and a spring located in said bore, said plunger urged by saidspring into abutting engagement with said upper plate with a springforce.
 9. The apparatus of claim 8, wherein said spring force isselectively adjustable.
 10. The apparatus of claim 9, further comprisinga threaded fastener adjacent to said spring, said fastener adapted toengage said spring and thereby adjust a length of said spring, wherebysaid spring force is selectively adjustable.
 11. The apparatus of claim9, further comprising a threaded fastener adjacent to said spring, saidfastener being adapted to engage said spring and thereby adjust a lengthof said spring, whereby said spring force is selectively adjustable. 12.The apparatus of claim 10, wherein said upper plate is brought intoabutment with said shell consequent to said spring force being overcomeby said imposed force.
 13. The apparatus of claim 1, wherein a pair ofopenings extends through the upper plate, and further comprising: aplurality of slides sandwiched between said lower plate and said upperplate, each of said slides secured to each of said lower and upperplates, said lower and upper plates linearly movable relative to eachother through said slides; and a shoulder bolt received through each ofsaid openings and secured to the lower plate, whereby said upper plateand said lower plate are maintained in parallel and adjacent to oneanother and said relative movement is linear and limited by the size ofsaid openings.
 14. The apparatus of claim 13, wherein said forcemeasuring element is a load cell providing an electrical outputindicative of the hitter's leg drive force level.
 15. The apparatus ofclaim 13, wherein said force measuring element comprises: a cylindricalshell having an axial terminal end and an axial bore extendingtherethrough; a plunger located in said bore and projecting beyond saidshell terminal end, said plunger engaged with said upper plate; a springlocated in said bore, said plunger urged by said spring into abuttingengagement with said upper plate with a spring force; and a threadedfastener adjacent to said spring, said fastener adapted to engage saidspring and thereby adjust a length of said spring, whereby said springforce is selectively adjustable; wherein an audible sound output isgenerated in response to said spring force being overcome by saidimposed force and said upper plate is consequently brought into abutmentwith said shell.
 16. A method of training to hit a pitched ball with abat, said method comprising the steps of providing a ground engagingplate; providing a foot engaging plate slidingly connected to saidground engaging plate and disposed in parallel to said ground engagingplate; providing a force measuring element disposed between andfunctionally attached to said plates; measuring the force between platesas a user swings at a pitched ball; adjusting the hitter's stance; andrepeating the adjusting and measuring steps until a desired force ismeasured.
 17. The apparatus of claim 1, wherein a pair of openings isprovided through the upper plate, and further comprising: a shoulderbolt received through each of said openings and secured to the lowerplate, whereby said upper and lower plates are maintained in paralleland adjacent to one another and said relative movement is linear andlimited by the size of the openings.
 18. The apparatus of claim 17,wherein said openings are oval shaped.
 19. The apparatus of claim 17,wherein said output comprises an audible sound.
 20. The apparatus ofclaim 17, wherein said force measuring element comprises: a cylindricalshell having an axial terminal end and an axial bore extendingtherethrough; a plunger located in said bore and projecting beyond saidshell terminal end, said plunger engaged with said upper plate; and aspring located in said bore, said plunger urged by said spring intoabutting engagement with said upper plate with a spring force.
 21. Theapparatus of claim 20, wherein said spring force is selectivelyadjustable.
 22. The apparatus of claim 13, wherein said force measuringelement comprises: a cylindrical shell having an axial terminal end andan axial bore extending therethrough; a plunger located in said bore andprojecting beyond said shell terminal end, said plunger engaged withsaid upper plate; a spring located in said bore, said plunger urged bysaid spring into abutting engagement with said upper plate with a springforce; and a threaded fastener adjacent to said spring, said fasteneradapted to engage said spring and thereby adjust a length of saidspring, whereby said spring force is selectively adjustable; wherein anaudible sound output is generated in response to said spring force beingovercome by said imposed force and said upper plate is consequentlybrought into abutment with said shell.
 23. The apparatus of claim 20,wherein said force measuring element further comprises a threadedfastener provided adjacent said spring, said fastener being adapted toengage said spring and thereby adjust a length of said spring, wherebysaid spring force is selectively adjustable.
 24. The apparatus of claim20, wherein said output is an audible sound generated by said upperplate hitting said shell when said spring force is overcome.
 25. Theapparatus of claim 17, further comprising: a plurality of slidessandwiched between said upper plate and said lower plate, each of saidslides secured to each of said lower and upper plates whereby said lowerand upper plates are linearly movable relative to each other.
 26. Theapparatus of claim 25, wherein said force measuring element comprises: acylindrical shell having an axial terminal end and an axial boreextending therethrough; a plunger located in said bore and projectingbeyond said shell terminal end, said plunger engaged with said upperplate; a spring located in said bore, said plunger urged by said springinto abutting engagement with said upper plate with a spring force; anda threaded fastener provided adjacent said spring, said fastener beingadapted to engage said spring and thereby adjust a length of saidspring, whereby said spring force is selectively adjustable; whereinsaid output is an audible sound generated by said upper plate hittingsaid shell when said spring force is overcome.